| Literature DB >> 27144280 |
Valeria Boron1, Joseph Tzanopoulos1, Jenny Gallo2, Jorge Barragan3, Laura Jaimes-Rodriguez4, George Schaller5,6, Esteban Payán2.
Abstract
Large carnivores such as jaguars (Panthera onca) are species of conservation concern because they are suffering population declines and are keystone species in their ecosystems. Their large area requirements imply that unprotected and ever-increasing agricultural regions can be important habitats as they allow connectivity and dispersal among core protected areas. Yet information on jaguar densities across unprotected landscapes it is still scarce and crucially needed to assist management and range-wide conservation strategies. Our study provides the first jaguar density estimates of Colombia in agricultural regions which included cattle ranching, the main land use in the country, and oil palm cultivation, an increasing land use across the Neotropics. We used camera trapping across two agricultural landscapes located in the Magdalena River valley and in the Colombian llanos (47-53 stations respectively; >2000 trap nights at both sites) and classic and spatially explicit capture-recapture models with the sex of individuals as a covariate. Density estimates were 2.52±0.46-3.15±1.08 adults/100 km2 in the Magdalena valley, whereas 1.12±0.13-2.19±0.99 adults/100 km2 in the Colombian llanos, depending on analysis used. We suggest that jaguars are able to live across unprotected human-use areas and co-exist with agricultural landscapes including oil-palm plantations if natural areas and riparian habitats persist in the landscape and hunting of both jaguar and prey is limited. In the face of an expanding agriculture across the tropics we recommend land-use planning, adequate incentives, regulations, and good agricultural practices for range-wide jaguar connectivity and survival.Entities:
Mesh:
Year: 2016 PMID: 27144280 PMCID: PMC4856405 DOI: 10.1371/journal.pone.0153973
Source DB: PubMed Journal: PLoS One ISSN: 1932-6203 Impact factor: 3.240
Fig 1Study areas.
Location of the sites in regard to the Jaguar Corridor and Jaguar Conservation Units (JCUs) in Colombia [15,24,33], and map of the study sites with camera locations. Site-1 is part of the Magdalena River valley, while Site-2 is located in the Orinoco River basin. Both sites were surveyed in 2014.
Parameters and survey features for Site-I and Site-II.
| Site-I | Site-II | |
|---|---|---|
| Location | Magdalena River valley | Orinoco River basin |
| Survey period | April-August 2014 | April-May 2014 |
| Traps active | 47 | 52 |
| Trap nights | 2251 | 2457 |
| Minimum Convex Camera polygon (km2) | 154.8 | 151.3 |
| N recorded | 10 | 6 |
| MMDM (km) | 4.2 | 5.7 |
| Effective sampled area (km2) | 396.2 | 537.2 |
N = Number of individuals; MMDM = Mean Maximum Distance Moved
Model selection parameters for both Capture-Recapture (CR) and Spatially Explicit Capture Recapture (SECR) models at Site-I and Site-II.
| Site-I Magdalena River valley | Site-II Orinoco River basin | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| AIC | ΔAIC | W | K | Dev. | AIC | ΔAIC | W | K | Dev. | ||
| CR Mh | 130.2 | 0 | 0.55 | 2 | 108.4 | CR Msex | 75.4 | 0 | 0.60 | 2 | 65.4 |
| CR M0 | 130.6 | 0.4 | 0.45 | 1 | 112.7 | CR Mh | 76.6 | 1.2 | 0.33 | 3 | 62.2 |
| CR Msex | 138.8 | 8.6 | 0.00 | 3 | 121.6 | CR M0 | 79.7 | 4.1 | 0.07 | 1 | 69.4 |
| SECR.sex.g0 | 924.2 | 0 | 0.66 | 5 | 894.2 | SECR.sex | 612.5 | 0 | 0.66 | 6 | 588.5 |
| SECR.sex | 925.6 | 1.4 | 0.34 | 5 | 893.6 | SECR.sex.g0 | 614.0 | 1.5 | 0.32 | 5 | 592.0 |
| SECR.sex.σ | 937.3 | 13.1 | 0.00 | 6 | 907.3 | SECR.sex.σ | 619.8 | 7.3 | 0.02 | 5 | 597.8 |
| SECR.0 | 953.4 | 29.2 | 0.00 | 4 | 925.4 | SECR.0 | 628.7 | 16.2 | 0.00 | 4 | 608.7 |
AIC = Akaike Information Criterion; ΔAIC = difference in AIC values between each model and the model with the lowest AIC; W = AIC model weights; K = number of model parameters; Dev. = Model Deviances. Mh: capture probability varies between individuals; M0: null model, Msex: capture probability varies between males and females. g0 = probability of capture at the home range centre, σ = spatial parameter related to home range size; SECR.sex.g0: g0 varies between males and females; SECR.sex: both g0 andσ vary between males and females; SECR.sex.σ:σ varies between males and females; SECR.0: null model.
Density and parameters estimated by the two best Spatially Explicit Capture Recapture (SECR) models, i.e. SECR.sex and SECR.sex.g0, at Site-I and Site-II.
| Site-I Magdalena River valley | Site-II Orinoco River basin | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Value | SE | 95% LCI | 95% UCI | CV | Value | SE | 95% LCI | 95% UCI | CV | |
| g0 females SECR.sex | 0.051 | 0.020 | 0.024 | 0.106 | 39% | 0.009 | 0.005 | 0.003 | 0.024 | 56% |
| g0 males SECR.sex | 0.813 | 0.556 | 0.003 | 1.000 | 68% | 0.118 | 0.025 | 0.077 | 0.176 | 21% |
| σ females (km) SECR.sex | 1.507 | 0.147 | 1.245 | 1.822 | 10% | 2.327 | 0.693 | 1.315 | 4119 | 30% |
| σ males (km) SECR.sex | 1.674 | 0.174 | 1.366 | 2.051 | 10% | 1.426 | 0.129 | 1.195 | 1.701 | 9% |
| g0 females SECR.sex.g0 | 0.046 | 0.016 | 0.023 | 0.088 | 35% | 0.013 | 0.006 | 0.006 | 0.030 | 46% |
| g0 males SECR.secr.g0 | 0.999 | 0.000 | 0.999 | 0.999 | 0% | 0.108 | 0.022 | 0.071 | 0.159 | 20% |
| σ (km) SECR.sex.g0 | 1.617 | 0.042 | 1.537 | 1.701 | 3% | 1533 | 133 | 129 | 1818 | 9% |
SE = Standard error; LCI and UCI = lower and upper confidence intervals respectively; CV = Coefficient of Variation; D = Density. Density values are in bold. g0 = probability of capture at the home range centre, σ = spatial parameter related to home range size; SECR.sex.g0: g0 varies between males and females; SECR.sex: both g0 and σ vary between males and females; SECR.sex.σ: only σ varies between males and females; SECR.0: null model.